NC0024406_Report_20191023

& DUKE
Vr ENERGY.
Certified Mail # 7018 2290 0001 1877 5428
October 21, 2019
Sergei Chernikov, PhD
State of North Carolina
Department of Environmental Quality
Division of Water Resources
Complex NPDES Permitting Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Subject: Duke Energy Carolinas, LLC
Belews Creek Steam Station - #NC0024406
Bromide Reduction Evaluation Semi — Annual Report
Dear Dr. Chernikov:
pa'ews Creek Steam Station
Duke Energy Carolinas
3194 Pine Hall Road
Walnut Creek, NC 27609
As required by Condition A. (20) of the subject NPDES permit attached are three copies of the
Semi-annual status report summarizing Duke Energy's efforts to reduce bromide discharge and
potential subsequent Total Trihalomethane (TTHM) formation in downstream municipal water
treatment systems.
Should you have questions regarding this report, please contact Joyce Dishmon at 336-623-0238
or Joyce.Dishmon @duke-energy.com.
Yours ,
Reginald D. Anderson
General Manager III, Regulated Stations
Belews Creek Steam Station
Power Generating Carolinas East
Attachment

Belews Creek Steam Station
Bromide Reduction Evaluation NPDES Permit-NC0024406
Semi -Annual Progress Report
October 2019
Pursuant to Condition A.(20) Bromide Reduction Evaluation of the NPDES Permit — NC0024406.
Duke Energy submits this semi-annual progress report. This report is required to summarize on-
going investigations focused on minimizing bromide discharge at Outfall 003, 006, and 111 as
well as efforts aimed at reducing the formation of total trihalomethanes (TTHM) at downstream
water treatment plants.
• Duke Energy has worked cooperatively with the North Carolina Division of Water
Resources (DWR), the Town of Madison and City of Eden to address the bromide/TTHM
issues since being advised of the municipality's issues with TTHM formation.
• Bromide itself is not a health concern in surface waters. There is no water quality
standard for bromide and no NPDES permit limit.
• Duke Energy has provided direct technical expertise and financial assistance to Madison
and Eden to help address their respective TTHM issues.
Town of Madison
• No updated information new to report.
City of Eden
• No updated information new to report.
Belews Creek Steam Station
• Duke Energy has partnered with UNC-C and Electric Power Research Institute (EPRI) to
perform a lysimeter pilot at Mayo Power Plant that is reviewing halide sequestration and
encapsulation strategy from a longterm perspective.
• Belews Creek is currently planning for 50% natural gas co -fire capabilities by 4t" quarter
of 2019 and 2020 for Units 1 and 2, respectively. This modification to the operation of
the station is a result of other factors but is expected to have an added benefit of
decreasing the mass of bromide discharges.

• Belews Creek is currently rerouting outfalls 003 and 111 to the Dan River via outfall 006.
This modification is projected to be completed in November 2019. Outfall 003A was
previously re-routed on July 12, 2019.